Add typed account and password settings

- Add admin account list, create, role, delete, and password workflows
- Execute identity-checked mutations through the existing dispatcher
- Bound queued credential lifetime and wipe transient secrets
- Add explicit password generation with saved-value acknowledgement
- Handle self-revocation and uncertain outcomes without automatic
  retries
- Register optional account routes without disrupting terminal
  transports
- Expand host regressions and document contracts and pending target
  checks

Validated host suites and pio run; hardware validation remains pending.

docs/agent/architecture.md

@@ -152,6 +152,14 @@ The final administrator cannot be deleted or demoted. UART0 is trusted for initi
 
 NVS is not encrypted. Password verifiers improve password storage, but Wi-Fi credentials, legacy recovery credentials, and TLS/SSH private keys remain recoverable under physical flash extraction.
 
+## Typed Accounts settings (8D.10)
+
+Current slice 2 extends the same dispatcher slot to create/password and self role/delete/password. Mutation bodies are 768 bytes/four receives; results stay secret-free, 96 bytes, replaceable and session-bound. Conditional password mutation checks identity under the canonical database mutex. A one-second firmware-lifetime ESP timer cancels/wipes non-executing queued credentials at their 30-second deadline plus timer/scheduling latency; dequeue wipes shared inputs after copying, and dispatcher-local credentials persist until admitted work returns. This is not a hard execution/erasure deadline. Separate bodyless admin/Origin/CSRF POST `/api/settings/accounts/generate-password` returns a 24-character value before any commit, without retained retrieval. UI generation has a 60-second best-effort lifetime and context-bound saved acknowledgement before separate submission; JavaScript cannot securely wipe strings. Self revocation may prevent final response/result access; disconnect/401 proves neither success nor cancellation. Browser-shell restrictions and UART0-only bootstrap/recovery remain unchanged. The generated endpoint is independently optionally registered, with failure isolation/restart coverage and 23 handlers. Implementation is complete, host-tested/build-verified; target validation/signoff remains pending. Parent build: 25.61 s, 95,908 B RAM / 1,694,237 B flash; timer runtime costs and stack/heap margins remain unmeasured. No task/stack/queue depth/socket expansion or 8D.11 work. Current contracts and attributed host evidence: `docs/phase8d10_implementation.md`.
+
+**Historical slice 1 architecture (superseded scope/counts, retained evidence):**
+
+`web_account_settings` supplies an optional admin-only compact account list and one session-bound role/delete operation/result slot, separate from Serial's slot but executed on the same dispatcher queue. HTTPD authorizes/parses/queues; the dispatcher revalidates the initiating login/admin and 30-second dequeue deadline, then calls conditional database mutations and best-effort target web/SSH revocation after success. `user_database_get_accounts()` copies at most eight username/role/ID/auth-generation records under the existing mutex with zero wait and no key/password fields. `user_database_delete_current()` and `user_database_set_role_current()` compare target identity under the mutation lock and share canonical CLI commit/invariant logic; stale selection never intentionally mutates a replacement account. Results are replaceable, not durable/idempotent, and already-admitted work can complete after logout. Self-target, create/password/generated-secret workflows remain unavailable in this slice; bootstrap/recovery remain UART0-only. Accounts UI confirms mutations, retains visible stale lists/outcomes during bounded auto-check/refresh and fences navigation/session changes without changing broker ownership. Three optional routes bring HTTPD handlers to 22; six sockets/no LRU and existing tasks/stacks/queue depth remain. See `docs/phase8d10_implementation.md` for limits and pending target checks.
+
 ## Typed Serial settings (8D.9)
 
 `web_serial_settings` admits strict bounded admin cookie/Origin/CSRF JSON into one static session-bound operation/result slot, queuing only a non-reused ID on the existing administration dispatcher. HTTPD never runs serial/NVS mutations. The dispatcher checks session/principal currentness and a 30-second dequeue deadline before canonical Apply/Start/Stop/Save/Load/Defaults/Reset APIs; already admitted work may complete after logout. A blocked dispatcher retains the slot, not a timed job cancellation. Results are login-isolated and replaceable after completion; no durable history/idempotent retry guarantee. After acknowledgement the UI checks at one-second intervals, bounded to 10 GET attempts and a 15-second overall deadline including session checks, then automatically refreshes working values for known terminal outcomes. Errors/exhaustion use manual recovery; no automatic mutation retries or navigation resumption. Settings remain visible with stale/pending labels; only Reset confirms saved-NVS overwrite. Selecting the current view is a no-op. Settings UI retains uncertain-result warnings, explicit RAM/NVS/discard explanations and both terminal sockets/lease. Two optional exact GET/POST registrations bring the URI budget to 19, with six sockets and unchanged tasks/stacks/queue depth. `/api/status` also uses the zero-wait serial snapshot and emits `running:null` when unavailable. See `docs/phase8d9_implementation.md` for resource and target-pending evidence.